Vector 3S crank length keeps reverting to factory default (172.5mm)

I have a Vector 3S power meter which I use with a FR935, an Edge130 and the Garmin Connect app.

The issue I am getting is low power measurements. It works for a period of time, (say 1 to 3 rides) then unexpectedly changes and reports lower power (materially lower so I can physically tell its not outputting what it should, say 40W lower). When I look into the settings, I think what is happening is the power meter is resetting the crank length from 160mm (which is correct and what I actually ride with) to 172.5mm (the default). I then try to update it to 160mm again which is very temperamental. I have tried using both the FR935 and the Edge 130 - once I have input the correct length, all looks well and the unit will say 160mm, but doesn't seem to actually make any changes to the power despite saying on the watch/computer the updated crank length. If I then use the GC app, the app reports the 172.5mm where the watch/computer are are reporting the 160mm. With some perseverance I can get the setting to update with the app, but it takes 5-6 attempts before it correctly reports back the 160mm, and then reports the correct power. This then works for 1-3 rides, and then resets again.

Any ideas as to what is going on here? I worry I am using too many devices with the power meter so I have tried removing the watch, but I need to bike computer for riding and the app is the only thing that seems to update it, so need that too.

Any thoughts/advice desperately welcome!!

Many thanks in advance

  • I would recommend disconnecting the Vector pedals from the phone app. There is no real need for you to have that pairing as you have a head unit that can perform any updates if needed.

    I think once you have just the FR935 and Edge 130 connected and with crank length settings that things will remain at the correct length.